Add-on unit for connecting to a mobile station and a mobile station

ABSTRACT

An auxiliary unit, adapted to be coupled to a mobile station comprising a basic element containing components necessary for data transmission, analyses and storage, as well as a sensor element containing a sensor suitable for the non-invasive measuring of a person&#39;s bodily functions and the special electronics required by the sensor. This means that different kinds of non-invasive measurements, such as ECG, EEG, EMG, blood pressure and respiratory flow, can be taken by changing the mere sensor element.

The present invention relates to an auxiliary unit, to be coupled to amobile station, and the mobile station.

Information on patients' bodily functions has already previously beensent by phone from a measuring point to a nursing unit. InternationalPatent Publication WO 94/01039 describes the transmission of a patient'sECG at a digital radio frequency from a measuring point (patient) to anursing centre. The publication describes a new type of sensor forrecording the ECG.

Digital mobile stations, such as portable GSM mobile phones, provideentirely new opportunities to control remotely patients' different kindsof bodily functions. The technical problem has been that the follow-upof different kinds of bodily functions requires several different typesof auxiliary devices to be coupled to a transmitter, which mostly carrythe same electronics but have different kinds of sensors, of course.

An auxiliary device, to be coupled to a mobile station, has now beeninvented, the device having a separate sensor element, which is replacedaccording to the bodily function measured at a given moment.

Thus, the object of the invention is an auxiliary unit intended to becoupled to a digital wireless telephone. This auxiliary unit comprises abasic element, which contains the components necessary for datatransmission, analyses and storage. The auxiliary unit also comprises asensor element, which contains a sensor suitable for the non-invasivefollow-up of a person's bodily functions, as well as the specialelectronics required by this sensor.

The auxiliary unit, according to the invention, is characterised in thatit comprises a basic element, which contains components necessary fordata transmission, analyses and storage, and a sensor element, whichcontains a sensor suitable for non-invasive measurement of a person'sbodily functions, as well as special electronics required by the sensor.The mobile station, according to the invention, is characterised in thatit comprises components necessary for data transmission of anon-invasive measurement, analyses and storage, a sensor element, to becoupled thereto detachably, which contains a sensor suitable fornon-invasive measurement of a person's bodily functions, as well asspecial electronics required by this sensor.

The invention will be discussed below in detail by referring to theenclosed drawings, of which

FIG. 1 illustrates the assembly of equipment according to the invention,

FIG. 2 illustrates the implementation of a basic unit as a blockdiagram,

FIG. 3 illustrates a sensor unit intended for the recording of the ECG,EEG and EMG,

FIG. 4 illustrates a sensor unit intended for the measuring of a bloodpressure, and

FIG. 5 illustrates a sensor unit intended for the measuring ofrespiration.

FIG. 6 illustrates the basic unit integrated as part of a mobile stationand the sensor units coupled directly to the mobile station.

FIG. 1 illustrates the different elements of the inventions; a mobilestation, such as a mobile station 10, whereto an auxiliary unit 20according to the invention can be coupled, which in turn comprises atleast two elements, i.e., a basic element (basic unit) 21 and a sensorelement (sensor unit) 22, which can be easily replaced according to thefunction measured or several of them can be connected in sequence.

The basic unit 21 and the sensor unit 22 are coupled to the mobilestation 10, e.g., to a digital GSM mobile phone utilising a dataconnection 12 included therein. If necessary, several sensor units 22can be connected to the basic unit 21 in a pile, as illustrated in FIG.1, by equipping the sensor units 22 with the same kind of connection asthe basic unit 21.

The function of the basic unit 21 is to launch the measuring of therequired bodily functions, to carry out the digitising of the measuringsignals, to store the measuring results in a memory and, if necessary,to transmit these results, by mobile phone, to a nursing unit in therequired form. If necessary, the basic unit 21 directs the user with thehelp of a display 13 of the phone and receives the user's commandsthrough a keyboard 14 of the phone. The basic unit also produces theoperating voltages required by the sensor units either from the powersupply (battery) of the mobile phone or from a separate power supplyunit 11, which can be coupled to the basic unit.

The sensor units 22 contain the measuring units, the couplings included,relating to each bodily function, as well as the necessary measuring andcontrol electronics so that the unit could produce, for the basic unit21, an initial analogue voltage proportional to the measuring quantity.The sensor units 22 also contain an internal analogue and digitalcombination bus 23 by means of which the control and measuring signalsof the units, located farther down in the sensor unit pile, aretransmitted to the basic unit. The operating voltages, required by thesensor units, which are produced, e.g., in the basic unit, are alsotransmitted through this bus 23. The sensor units 22 have beenimplemented so that the basic unit 21 is automatically capable ofrecognising which sensor units have been coupled thereto. Recognitioncan be carried out on the basis of a signal received from the sensorunit or, e.g., so that a bus connector 23 comprises several connectors,whereupon a different sensor unit produces a signal for a differentconnector. An output connector 23 of the bus is connected to an inputconnector 26. The connection of the bus 23 to the mobile phone isestablished through a basic unit 15 and the phone's data connection 12.

If necessary, the sensor unit pile and the basic unit can also be usedwithout the mobile phone 10 which, in this case, can be replaced by apower supply unit 11 to be connected to the basic unit. This unit can bea battery packet made using a similar technique than in the mobilephone. Thus, in this case, the power supply unit 11 can also be abattery, coupled to the mobile phone, to be connected to the batteryspace of the mobile phone through a connector 16. The basic unit,according to the present invention, can also be integrated as part ofthe battery 11, to be coupled to the mobile phone, so that the basicunit's electronics and battery cells are within the same case. Thus,this kind of integrated auxiliary unit can be used independently orcoupled to the mobile phone, whereupon the battery 11 feeds energy toboth the mobile phone 10 and the basic unit 21, as well as to the sensorunits 22 coupled thereto. In this case, data are preferably transmittedbetween the mobile phone and the basic unit through the connectorslocated within the mobile phone's battery space.

The advantage of the structure is that the use of different kinds ofsensors does not require several different kinds of versions of thecomplicated basic element. The basic element 21 contains appropriatelyanalog/digital converters, a microprocessor for controlling theoperations, as well as a memory for storing the data. The memory ispreferably non-volatile. The microprocessor is responsible for themeasuring protocols, the analysing of the results and the data trafficto the telephone. The basic element can also contain a subscriberidentity module (SIM), wherein the user's patient information, thenursing unit's identifiers, etc. have been stored.

In addition to the sensor itself, the sensor element 22 also containsthe cables belonging thereto and, appropriately, also the differentialamplifiers and filters for the signal of the measured bodily function.

Below we will discuss, by way of example, the implementation of thebasic unit and different kinds of sensor units by referring to FIGS.2-5.

FIG. 2 illustrates, in the form of a block diagram, the implementationof the basic unit presented above. The unit has, as a central component,a microprocessor 210 which controls the operation of an auxiliary unit,according to the invention, and the function of which is to provide forthe measuring protocols, the analysing of the results and the datatraffic to the mobile phone. The non-volatile memory is preferably anEEPROM circuit 211, which contains the microprocessor's program forcarrying out the different operations, as well as possible calibrationtables for the sensors. The memory 211 is also used for longer-termstorage of the measuring results. Typically, the capacity of the EEPROMcircuit is several dozen kilobytes. In addition, a RAM circuit 212 isused as a memory, the RAM circuit being used for operations required bythe program, as well as for temporarily storing the measuring resultsand the result of the analyses normally while the microprocessor isperforming a program retrieved from the memory 211.

A subscriber identity module (SIM) 214, used in GSM telephones, ispreferably coupled to the mobile phone 10. In FIG. 2, it has beenpresented as part of the basic unit in order to illustrate itsutilisation for an auxiliary unit, according to the invention, whereuponthe SIM 214 can contain the patient's identity information, theidentifiers of the nursing unit, the limit and emergency values relatingto different bodily functions, etc. In this case, these data aretransmitted to the basic unit through the mobile phone's data connection12. Alternatively, the basic unit contains a separate, replaceableintelligent card 214 of its own, which is, e.g., of the size of a smallsubscriber identity module and wherein the above-mentioned data arestored.

For connecting the basic unit to the mobile phone, the basic unit has amobile phone connection block 214, which provides for the electricadaptation of the signals and the data between the phone and the basicunit. Hence, the connection block 214 can be implemented in the same wayas the data cards known in connection with the mobile phone, which carryout the adaptation of the data. An operating voltage generating element215, illustrated in FIG. 2, produces from the output voltage, providedby the mobile phone or the separate power supply unit 11, the operatingvoltages required by the sensor units, e.g., according to the switchmadepower supply principle. This unit also provides for the sensor elements'power consumption automation. An analog-digital converter block 216converts the analogue voltages, coming from the sensor units, into adigital form. The converter 216 is, e.g., a 12-bit converter and itsconversion speed is 200-500 samples a second. The connection between thebus 23 and the basic units' other components is implemented by means ofan analogue multiplexer 217 which selects, controlled by themicroprocessor, the signal of the sensor unit which should be digitisedat a given moment. The connection between and the combination of themultiplexer 217 and the AD converter 216 is so fast that it is possibleto serve several sensor units 22 simultaneously.

In addition to the microprocessor 210, the basic unit may contain aseparate control unit 218, which provides for the control signals of thesensor units that need to be controlled by the processor duringmeasuring. Alternatively, this operation can be carried out directlyunder the control of the microprocessor.

The basic unit has a push button 24 as a simple user interface Ul. Bypressing the button, the user of the device can inform of thecommencement or termination of measuring. In addition, the unit has amulticoloured signal light 25, which informs the user whether theequipment is in working order, whether the sensors have been correctlyconnected and whether the signal coming from the sensor unit isappropriate. In addition, by means of the signal light 25, it is alsopossible to inform of the measuring session's time of termination. Thepush button and the signal light together enable the device to be usedwithout a mobile phone. If a mobile phone has been coupled to theequipment, it is possible to carry out the corresponding operations bymeans of a keyboard 13 and a display 14.

In the following, we will discuss, by way of example, three differentimplementations of a sensor unit suitable for the non-invasive measuringof a biosignal.

FIG. 3 illustrates a sensor unit suitable for recording anelectrocardiogram (ECG), an electroencephalogram (EEG) and anelectromyogram (EMG). The recording of these three electrograms issimilar, in principle, because all of them measure small potentialdifferences between electrodes placed on the skin (typically, in thecase of an ECG, hundreds of microvolts, whereas in the case of an EEG orEMG, microvolts or dozens of microvolts). There are differences in thestructure of the skin sensors, in the amplification required by thesignals, as well as in the frequency filtering. FIG. 3 illustrates onepossible typical connection, when using three sensors 31-33 to produce asingle output voltage. The aim is to produce from the measuring signals,by means of differential amplifiers 34-36, as reliable a commonreference potential as possible, against which one or more measuringsignals are measured. The bus structure between the sensor units and thebasic unit also allows multichannel measuring if necessary. A low-passfilter 37, included in the unit, removes, from the measuring signals,the high (interference) components hindering the analog-digitalconversion, after which the signal is lead from the sensor unit outputto the basic unit.

As for the ECG, the software of the basic unit includes the detection ofa characteristic tension pulse (so-called ORS complex) produced by theheart beat and, through it, the computation of the average pulsedensity, which is carried out by means of the microprocessor 210. Inaddition, some clear functional disturbances of the cardiac muscle canbe deduced from the shape of the pulse in question, of which the devicecan inform the user. A momentary heart rate and the original ECG signal(sampling speed 200 samples a second, resolution 12 bits) are stored inthe memory 211. A typical measuring period lasts for a few minutes. Inlong-term registration (e.g., 24 hours), only a momentary heart rate isstored.

FIG. 4 illustrates a sensor unit suitable for measuring a bloodpressure. In this sensor structure, a continuous blood pressure ismeasured from a person's finger 41. The equipment consists of aninfrared transmitter-receiver pair 42 a, 42 b, by means of which theblood amount in the finger is measured and, through it, the bloodpressure in the finger, as well as of a pneumatically operated fingersleeve 43. The aim is to continuously produce in the sleeve 43, by meansof an air pump 44, a pressure which precisely compensates for thevariation of pressure caused by the circulation. In this situation, theintensity of the IR radiation penetrating the finger remains stable. Inthis case, a control voltage 46 of an adjusting valve 45, included inthe system, is directly proportional to the blood pressure. To ensurethat the scope of dynamics of the adjustment would be as wide aspossible, in addition to a signal 47 of the IR detector 42 b, themagnitude of the adjustment of the valve 45 is also established on thebasis of a pressure signal 49 of the sleeve. For this purpose, theequipment also includes a pressure sensor 48 which measures the pressureof the sleeve.

The function of the basic unit's software, relating to blood pressure,is to adjust before the actual measuring begins the basic pressure ofthe sleeve so that the required scope of dynamics is reached. Afterthis, the software should detect the minimum and maximum value (i.e.,so-called diastolic and systolic blood pressure) of the blood pressurepulse relating to each heart beat and compute the actual pressure valueson the basis of the calibration values. The activities of the softwares(stored in the EEPROM memory 211) are carried out by means of themicroprocessor 210. The pressure values are transmitted from the sensoroutput to the basic unit as a voltage. If the equipment also contains anECG unit, it is possible to combine the two acts of measuring, whereupondetection becomes easier.

FIG. 5 illustrates a sensor unit suitable for measuring respiration. Thefunction of the unit is to measure the flow of a person's inhalation andexhalation. This is done by blowing into a straight pipe 50 that has acoarse-meshed net 51 installed at its other end. While the air flowsthrough the net either over-pressure (exhalation) or under-pressure(inhalation) is produced in relation to the outside air pressure. Thispressure differential is proportional to the flow. The pressuredifferential is measured using a capacitive pressure differential sensor52. The capacitance in question is part of a voltage controlledoscillator (VCO) 53. When the pressure changes, the capacitance inquestion also changes, whereupon the frequency of the oscillatorchanges. The output signal of the oscillator has been connected to afrequency-voltage converter 54 from the output of which a voltagesignal, directly proportional to the frequency, is obtained. Thiscontrol voltage has been connected through a possible frequency changingmultiplier 55 to a control input determining the frequency of the VCO.The final result is that the control voltage automatically settles atsuch a value that the frequency of the oscillator remains stablealthough the capacitance of the pressure differential sensor changes. Acontrol voltage 56, produced by the converter, which is lead to thebasic unit as the sensor unit's input is, thus, proportional to thepressure differential and, through it, to the respiratory flow.

Because the measuring of the flow presented above is rather non-linear,the software of the basic unit must correct the measuring result togenuine flow readings using, e.g., a calibration table. After this, theflow signal is integrated over time, whereupon the momentary air volumeof the lungs is obtained. Both the flow and volume signal can be storedfor further analyses. In addition, the maximum inhalation and exhalationflow can be computed on the basis of the flow signal (so-called PEF andPIF measuring). These corrections, integrations and computations arecarried out by means of the microprocessor 210.

Other possible quantities describing bodily functions can be, e.g., bodytemperature (with a thermoelement, etc.), oxygen content of the blood(the absorption of oxidised and inoxidised blood is measured from theauricle using two characteristic wavelengths of visible light and theirquotient is computed), blood sugar level, heart and breath sounds (usinga sensitive microphone).

The equipment 20 has two measuring modes which can be used for differentkinds of measuring needs:

(a) A biosignal is measured for one minute or longer, and the entiremeasuring series, the possible results of the analyses included, isstored in the basic unit's non-volatile memory 211. These signalsinclude, e.g., ECG, EEG, EMG, blood pressure and respiratory flow.

(b) The quantity is measured only for as long as it is necessary toobtain a reliable value. These include, e.g., momentary blood pressure,PEF/PIF, blood oxygen concentration, blood sugar concentration,temperature. In this case, it is a question of long-term follow-up(e.g., 24 hours). Only these individual values are stored in the memory211 or 212.

The basic unit, according to the invention, can have, e.g., fourdifferent basic operating modes according to which the data, stored inthe memory 211 or 212, can be processed in four different ways:

(1) After measuring, the user is presented, e.g., on the display 13 ofthe mobile phone, simple statistical results computed on the basis ofthe signal, such as the average pulse density and variability, theaverage systolic and diastolic blood pressure or the maximuminhalation/exhalation flow, as well as the possible notices of exceededlimit values or other abnormalities observed. After this, the materialcan be deleted from the memory. If necessary, the patient may contactthe physician attending him by means of his mobile phone as normal.

(2) The data, collected by means of either the measuring mode (a) or(b), and the results of the analyses are sent by the user to a healthcentre or a central hospital, to the physician attending him, in theform of graphic telefax output which also contains the patientidentifiers, etc. Thus, the physician can immediately visually study thebehaviour of the vital function parameters and quickly give feedback tothe user. The method does not require any special equipment other thantelefax equipment at the receiving end.

(3) All the data are sent, through a mobile phone, to a nursing unit inthe form of a digital file. This provides an opportunity to make morecomplicated and fundamental analyses of the measuring signalsparticularly in connection with multichannel measurements. The methodrequires that the receiving end has appropriate computer hardware,telecommunication connections included. This is also well suited for a(first aid) physician who uses the equipment as part of the initialtreatment diagnostic devices.

(4) The data, collected by means of either the measuring mode (a) or(b), are transferred to a nursing unit without the user of the equipmentsending them. This remote discharge method enables patients in poorhealth, in particular, to be watched over round-the-clock, if necessary,provided that the equipment is equipped with the possibility of startinga measuring session by telephone. Also in this alternative, it isimportant that the physician and the patient are able to communicateorally.

Individual measuring results can also be sent through a mobile phone ina short message which, in the GSM system, is known as a short messageservice (SMS). The invention can also be used for the non-invasivemeasuring of other bodily functions and for analysing and reporting themeasuring results. This is done simply by replacing the sensor element.By miniaturising the sensor mechanics, the basic unit and the sensorunit can be made sufficiently small and light. As shown in FIG. 6, thebasic unit 321 can also be integrated as part of a mobile station 310,whereupon the sensor units 22 are coupled directly to the mobile station310 via data connector 312.

This paper presents the implementation and embodiments of the presentinvention with the help of examples. It is obvious to a person skilledin the art that the present invention is not restricted to details ofthe embodiments presented above, and that the invention can also beimplemented in another form without deviating from the characteristicsof the invention. The embodiments presented above should be consideredillustrative, but not restricting. Thus, the possibilities ofimplementing and using the invention are only restricted by the enclosedclaims. Consequently, the various options of implementing the inventionas determined by the claims, including the equivalent implementations,also belong to the scope of the invention.

What is claimed is:
 1. An auxiliary unit, for non-invasive measurementof a person's bodily functions, to be coupled to a mobile station, theauxiliary unit comprising a basic element and a sensor element, thebasic element contains components necessary for data transmission,analyses and storage relating to non-invasive measurement of a person'sbodily functions, wherein the sensor element contains a sensor suitablefor non-invasive measurement for a person's bodily functions andmeasuring and control electronics required by this sensor, and whereinthe sensor element is detachably coupled to the basic element, the basicelement being further adapted to receive electrical signals from thesensor element related to the non-invasive measurements and convert thesignals into a protocol suitable for use by the mobile station.
 2. Anauxiliary unit according to claim 1, characterised in that the basicelement (21) and the sensor element (22) comprise means (23, 26) forconnecting the sensor element to the basic element detachably.
 3. Anauxiliary unit according to claim 1, characterised in that the sensorelement comprises means (23) for connecting another sensor elementthereto.
 4. An auxiliary unit according to claim 1, characterised inthat the battery (11) has been arranged to feed energy to the auxiliaryunit (20) and the mobile station (10) to be coupled thereto.
 5. Anauxiliary unit according to claim 1, wherein said special measuring andcontrol electronics is configured to produce a signal proportional tothe measuring quantity.
 6. The mobile station of claim 1 wherein thebasic element includes an analog to digital converter for converting thesignals received from the sensor element.
 7. The auxiliary unit of claim1 wherein the special measuring and control electronics required by thesensor includes measurement and control electronics adapted to allow thesensor element to convert the measured bodily functions into signalssuitable for use by the basic element.
 8. The auxiliary unit of claim 1wherein the special measuring and control electronics required by thesensor includes means for the sensor element to produce an initialanalog voltage proportional to a measuring quantity corresponding to thebodily function being measured.
 9. The auxiliary unit of claim 1 whereinthe mobile station comprises a mobile telephone.
 10. An auxiliary unitaccording to claim 1, characterised in that it has been integrated witha battery (11), to be coupled to a mobile station, comprising means (16)to be connected to a battery space of the mobile station.
 11. Anauxiliary unit according to claim 10, characterised in that the basicelement (21) comprises means (210, 211, 214) for receiving and storing asignal proportional to measuring and for producing the measuring data.12. An auxiliary unit according to claim 11, characterised in that thebasic element (21) comprises means (210, 214) for processing themeasuring data into a form to be transmitted through the mobile station(10).
 13. A mobile station comprising means for transmitting data andcomprising a sensor element for non-invasive measurement of a person'sbodily functions detachably coupled to the mobile station, the mobilestation comprises components necessary for non-invasive measuring datatransmission, analyses and storage, the sensor element contains a sensorsuitable for the non-invasive measuring of a person's bodily functionsand measuring and control electronics required by this sensor, whereinthe mobile station further comprises a means adapted to receiveinformation from the sensor element and convert the information into adata format compatible with a receiving station.
 14. The mobile stationof claim 13 wherein the mobile station is adapted to transmit theconverted information to a receiving station which is adapted to processthe converted information.
 15. The mobile station of claim 13 whereinthe special measuring and control electronics includes means to allowthe sensor element to convert the measured bodily functions into signalssuitable for use by the basic element.
 16. The mobile station of claim13 wherein the mobile station comprises a mobile telephone.
 17. Anauxiliary unit adapted to be coupled to a mobile station comprising: abasic element including components necessary for data transmission,analyses and storage; a sensor element including a sensor suitable fornon-invasive measurement of a person's bodily functions wherein thesensor element includes a connection device adapted to connect thesensor element to another sensor element; and electronics required bythe sensor.
 18. The auxiliary unit of claim 17 further comprising: anintegrated battery adapted to be coupled to a mobile station; and aconnection device adapted to connect the integrated battery to a batteryspace of the mobile station.
 19. The auxiliary unit of claim 18 furthercomprising a battery device that is adapted to feed energy to theauxiliary unit and the mobile station.
 20. The auxiliary unit of claim18 wherein the basic element further comprises a device adapted toreceive and store a signal proportional to a measurement signal and forproducing measurement data.
 21. An auxiliary unit, for non-invasivemeasurement of a person's bodily functions, adapted to be coupled to amobile station, the auxiliary unit comprising: a sensor elementincluding a sensor suitable for the non-invasive measurement of theperson's bodily functions, the sensor including measurement and controlelectronics adapted to allow the sensor element to convert the measuredbodily functions into signals suitable for use auxiliary unit; and abasic element including components for data transmission, analyses andstorage of information related to the non-invasive measurement of theperson's bodily functions, wherein the basic element is integrated witha battery device for the mobile station in a case, the battery devicecomprising means for being connected to a battery space of the mobilestation, the basic element being further adapted to receive electricalsignals from the sensor element related to the non-invasive measurementsand convert the received signals into a protocol suitable for use by themobile station; and wherein the sensor element is adapted to bedetachably coupled to the battery device integrated with the basicelement.
 22. The auxiliary unit of claim 21 wherein the mobile stationcomprises a mobile telephone.
 23. A mobile station comprising a batteryand an auxiliary unit for non-invasive measurement of a person's bodilyfunctions adapted to be coupled to the mobile station, the auxiliaryunit comprising: a basic element including components necessary for datatransmission, analyses and storage of information related to thenon-invasive measurement of a person's bodily functions; a sensorelement adapted to be detachably coupled to the mobile station, thesensor element including a sensor suitable for the non-invasivemeasurement of the person's bodily functions and control and measurementelectronics adapted to allow the sensor element to provide the basicelement with signals corresponding to the measured bodily functions; anda battery device of the mobile station wherein the basic element isintegrated as part of the battery device in a battery device case, thebattery device comprising means for connecting the battery device to abattery space of the mobile station, the basic element being furtheradapted to receive electrical signals corresponding to the measuredbodily functions from the sensor element and convert the signals into aprotocol suitable for use by the mobile station.
 24. The mobile stationof claim 23 wherein the mobile station comprises a mobile telephone.